HARVEST MOON

TONIGHT--THE HARVEST MOON: Tonight's full Moon has a special name--the Harvest Moon. It's the full moon closest to the northern autumnal equinox. In years past, farmers depended on the light of the Harvest Moon to gather ripening crops late into the night. Post-Edison, we appreciate it mainly for its beauty:

"I took this picture last night from an agricultural field--quite appropriate for the Harvest Moon," says photographer Maximilian Teodorescu of Magurele, Romania. "The high-resolution version contains some incredible details."

There's more: The Harvest Moon behaves in a special way. Throughout the year the Moon rises, on average, about 50 minutes later each day. But near the autumnal equinox, this difference shrinks to only 30 minutes. The reason is, at the beginning of autumn the Moon's orbital path makes a narrow angle with the evening horizon.

To a non-astronomer, that might sound like celestial trivia. But to sky watchers it makes a huge difference. For several nights in a row around the time of the Harvest Moon, the Moon rises at about the same time--sunset.  And you know what happens when the Moon rises at sunset....
Low-hanging moons are magnified by the Moon illusion, a well-known but still mysterious trick of the eye that makes the Moon seem much larger than it really is. Tonight at sunset, you could see a giant Harvest Moon. Happy autumn--and enjoy the show!

spaceweather.com